/**
 * FileName: VerifyCode
 * Author:   嘉平十七
 * Date:     2020/6/28 8:40
 * Description: 验证码
 * History:
 * notes：
 */
package com.test;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class VerifyCode {
    //设置宽高
    private int w=70;
    private int h=35;
    //定义随机
    private Random r=new Random();
    //可选字体
    private String[] fontNames ={"宋体","华文楷体","黑体","微软雅黑","楷体_GB2312"};
    //可选字符
    private String codes="23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKMNOPQRSTUVWXYZ";
    //背景色
    private Color bgColor=new Color(255,255,255);
    //验证码上的文本
    private String text;

    //生成随机颜色
    private Color randomColor(){
        //0-150，不包括150
        int red=r.nextInt(150);
        int green=r.nextInt(150);
        int blue=r.nextInt(150);
        return new Color(red,green,blue);
    }

    //生成随机字体
    private Font radomFont(){
        int index=r.nextInt(fontNames.length);  //获取字体数组长度
        String fontName=fontNames[index];      //生成随机的字体名称
        int style=r.nextInt(4);     //生成随机的样式，0（无样式），1（粗体），2（斜体），3（粗体加斜体）
        int size=r.nextInt(5)+24;   //生成随机字号，24~28
        return new Font(fontName,style,size);
    }

    //画干扰线
    private void drawLine(BufferedImage image){
        int num=3;  //一共画3条
        Graphics2D g2= (Graphics2D) image.getGraphics();    //画笔
        for (int i=0;i<num;i++){
            //随机生成坐标，生成两个点的坐标，即4个值
            int x1=r.nextInt(w);
            int y1=r.nextInt(h);
            int x2=r.nextInt(w);
            int y2=r.nextInt(h);
            g2.setStroke(new BasicStroke(1.5F));
            g2.setColor(Color.blue);    //干扰线蓝色
            g2.drawLine(x1,y1,x2,y2);   //画线
        }
    }

    //随机生成一个字符
    private char randomChar(){
        int index=r.nextInt(codes.length());
        return codes.charAt(index);
    }

    //创建BufferedImage
    private BufferedImage createImage(){
        BufferedImage image=new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
        Graphics2D g2= (Graphics2D) image.getGraphics();
        g2.setColor(this.bgColor);
        g2.fillRect(0,0,w,h);
        return image;
    }

    //外界调用这个方法，得到验证码
    public BufferedImage getImage(){
        //创建图片缓冲区
        BufferedImage image=createImage();
        //得到绘制环境
        Graphics2D g2= (Graphics2D) image.getGraphics();
        //用来装载生成的文本
        StringBuilder sb=new StringBuilder();
        //向图片中画4个字符
        for (int i=0;i<4;i++){
            String s=randomChar()+"";   //随机生成一个字符
            sb.append(s);               //把字母添加到sb中
            float x=i*1.0F*w/4;         //把int类型转换成float类型，把x轴分开，设置当前字符x轴的坐标
            g2.setFont(radomFont());    //随机字体
            g2.setColor(randomColor()); //随机颜色
            g2.drawString(s,x,h-5); //画图
        }
        this.text=sb.toString();        //把生成的字符串赋给this.text
        drawLine(image);                //添加干扰线
        return image;
    }

    //返回验证码上的文本
    public String getText(){
        return text;
    }

    //保存图片到指定的输出流
    public static void output(BufferedImage image, OutputStream outputStream) throws IOException {
        ImageIO.write(image,"JPEG",outputStream);
    }
}